Combined humidity and air flow control



July 6, 1965 l.. L. KRUEGER COMBINED HUMDII'Y AND AIR FLOW CONTROL FiledJune 24, 1963 I N VE N TOR.

azar/u ,4. IPM-'622 AIR FLOW United States Patent fce 3,193,641 PatentedJuly apprese 3,193,641 COMBINED HUMEDITY AND AIR FLOW CNTRL Loren L.Krueger, Minnetonka, Minn., assigner to Honeywell Inc., a corporation ofDelaware Filed June 24, 1963, Ser. No. 289,944 3 Claims. (Cl. 20d-31.9)

The present invention is concerned with an improved air llow responsivedevice. In particular, the device comprises a sail operated controlwherein the sail has a collapsible structure so that even though thesail is relatively large when extended, the sail can be collapsed tohave a small size for shipping purposes and for easy installation bypushing the collapsed sai-l through a small hole in an air flow duct.

The use of sail switches to respond to the movement for velocity of airin an air duct or air conditioning system is broadly old. These air flowresponsive devices or sail switches have a pivoted member which isconnected to `a large sail to `operate a switch when the sail moves froma rst to a second position upon the presence of air liow. In order toobtain suiiicient force to operate the switch, the area of the sail isrelatively large which makes such a control device quite bulky whichpresents a problem in the packaging and shipment of the device. Inaddition, when a .sail switch of the type commonly known in the priorart is mounted in an air ow duct or in the plenum of a furnace, somesort of adapter plate is generally used as the size of the sail is quitelarge with respect to the remaining port-ion of the control device.

The present invention is concerned with a control device having an airflow responsive sail. The sail is constructed by means of a collapsibleframework supporting a thin material sail whereby the sail can becollapsed by pulling the 'structure together. With such a collapsiblesail, the overall size of the control device can be reducedsubstantially to eliminate the previous extensive packaging required toVcontain devices of this type. The framework can be collapsed and heldby some clamping means to provide .a relatively compact device which canbe packyaged in a relatively .small container. Also'with such acollapsible sail, the control device can be readily installed on thejob. A relatively small hole can be made in the air flow duct or in theside of the furnace plenum, and the installation of the air owresponsive device is easily `acplished by holding the `sail in -acollapsed posit-ion and inserting the sail `through the small hole. Thesail then extends to Ia size necessary to provide the force needed uponthe movement of air in the duct.

An object of the present invention is to provide an air ilow responsivedevice having a collapsible sail.

Another object of the present invention is to provide a control devicehaving a switch actuated by a sail made of a collapsible frameworkwhereby the sail can be reduced to a relatively small size for packagingand installation through a small hole in an air flow duct.

Another object of the present invention is to provide a control devicehaving humidity responsive means and a collapsible air ow responsivedevice for operating a switch upon the presence of a predeterminedhumidity and air ow.

These and other objects will become apparent upon the study of thefollowing specification and drawing of which `FIGURE l is a prospectiveview of the control device showing the -switch housing, the supporthousing, and the collapsible sail.

FIGURE 2 is a `side cross-sectional View of the control device showingthe switch mechanism, the moisture responsive element, and the air ilowresponsive device.

FIGURE 3 is a schematic representation of a typical means of installingthe air llow responsive device with the' collapsible sail. n

Referring to FIGURE 1, the main switch housing 10 has a support housing11 connected thereto. Switch housing has a cover 12. Associated with thesupport housing y11 is an air flow responsive device or sail 13 whichresponds to the downward ow of air.

Referring to FIGURE 2, a cross-sectional view of a switch 14 containedin housing 10 is shown. The switch is of -a conventional type having amain housing 15 containing terminals connected electrically -to astationary contact Ztl and a movable switch operating member or blade 21to form a closed circuit when member 21 moves to the right to engagecontact 2.0. The electrical circuit is connected to the upper end 22 ofmember 21. An operating lever 23 has a detent member 24 engaging switchblade 21 at a mid-position 25. Switch blade 21 has a center portion 30which is anchored at its upper extremity 31 on a member 32 which isadjustable to change the control point of the switch. Member 32 isyfirmly attached at its upper end e33 to the switch housing 15 and is4contacted by a screw 34 adjusted by the `control point setting knob 35to change the control point ot the switch and of the control device.Another adjustment member controls the switch differential by limitingthe movement of blade 21 in the left direction or in the open switchposition. y

Lever 23 is pivoted about a iixed pivot 41 whereby when the lever is inthe downward position as shown, detent 24 pushes against blade 25 tohold the switch in an open circuit position as shown.

Air llow responsive device 13 comprises -a pivotally supportedcollapsible frame 80 connected to member 42 which is pivoted about a pin43 attached to support member 11. One 1extremity 44 of member 42 isconnected to .a bias spring 4S connected between member 44 and aprojection on support 11 to bias lever 44 in a counterclockwisedirection about pivot 43 to hold the sail 13 upward in a position asshown. Attached to member 44 at a pivoted support 51 is a second lever52 which engages the switch lever 23 to push the `switch lever downwardwhen the sail is in the position as shown so the contact 21 is` held`away from the fixed contact 2t) and the switch is open. Lever 52 has anlopen fork like end to not be positively attached to lever 23.

Upon the presence of air flow, sail 13 is moved downward to the positionshown by the dotted lines and lever 52 is pulled upward .against thebias spring to allow the switch lever 23 to move in a clockwisedirection. The switch 4blade 25 moves over center of the xed pivot point31 to close the contacts 21 and 20 and complete an electrical circuit. y

In addition to the air ow responsive device 13, a moisture or humidityresponsive device which responds to the amount of moisture in the air orrelative humidity comprises a plurality of lengths of moistureresponsive element 61 strung between a movable support 62 anda fixedsupport 63 attached to housing 11 which can be adjusted by anappropriate screw 64 to change the control point. A typical moistureelement is shown in the Russell N. Booth Patent 2,866,023. Lever 65which is pivoted about pin 79 on base 11 has the movablesupport 62connected at the upper end thereof. The lever 65 is spring biased in acounter-clockwise direction by a bias spring 71 connected between thelower extremity 72 of lever 65 and a projection 73 on support 11.Another projection 74 on lever 65 engages the switch lever 23 wherebywhen element 61 is relaxed and lever 65 moves in a counterclockwisedirection, lever 25 is held downward in a switch open position.

The air tlow responsive device or sail 13 as shown in FIGURE l comprisesa wire structure S0 which is attached to member v42 by afastening means81. The wire support structure is resilient so that when the extremeends 82 and 83 of the wire are pulled together, a sail made up of a thinsheet material 83 and held on the V shapedstructure willcollapse iii-fanmannerasv shown'in FGURE v3. M'When the conning force onsail 13isremoved, the resiliency of wire 8l) will cause the sail to extendaslshownin FIGURE l. i

Operation As shown in FIGURE 2, the switch is in an open position,andthe sail 13 isin the upper position as would befthe casewithno airfiow. Uponthe placement of the support member `11 in an air environmentsuchas in the diictvor plenum of a furnace, air flow downward againstsai1n13 vwould'` result in movement of lever i2 in a clockwise directionabout pin l43 to litlever 52. Since lever SZhhas anopen'lforkedshapeatthebottom, switch lever 2,3 will "not move upward under 'thespringfor'ce of blade 2lfaslong asthe moisture responsivedeviceresponds'. to thehumidity level or relative humidity above acertain value and projection .'74 is in a position tohold the switchlever `2,3 downward. Assuming that thehumidity of the air is below somepredetermined value, the element 61 wouldthen contract and pivot lever65in a counterclockwise directionfto lift member 74. The switch lever2,3'is free to move upward and, operate the `switch by allowingthfede't'ent A24 to remove thevp'r'essure from blade 25 so the bladecould snap over center and close the circuit between lblade 2`1`andcontact l20. If for any reason, the air o'w against sail 13 would stop,lever 5,2,would be effective to push the switch lever y23 downward andopen the switch even though the moisture level as sensed 'by elementhlwould be below the value required. With this type *of control', ahumidifier in afurnace could be controlled Ato bring 7aboutthe additionVof moistureto the air; however, the `humidiiier would fnot operatesaslong as there was 'no air flow.'

"'-With`f4'tlie collapsible sail 13 as shown in FIGURE 1,many"advantagesv are gained. As the size of the sail lis generallylarge'compared'with the remaining partof the control deviceincludin'gthe support lstructure `11 and the switch housing l1 0, the packaging ofsuch fa icontroldevicefheret'fore has been relatively expensive; Withrthe collapsible sail 1'3",the' sail'can bejreduced to a relativelysmall size commensurate withn the sizeof support member 11. In thismanner, the packaging problem is greatly reduced and the cost of anypackage or carton holding the control device is much lower.v i Duringthe installation bf the air fiowresponsive device, bym'eans'of asuitable fclamplor'appersonfs hand 90 as shownin FIGURE 3, the sail 13canjbe heldin a collapsed nian'ner andthe support housing 110i uthecont'rol device can be inserted into a relativelyV small hole 91 of anair flow duct 92. 'In this manner,V the installation4 of they controldevice/does not requirespecial mounting brackets for covering existinglarge holes heretofore nec? essary to installa sail operated controldevice. When the support housing 11 is inserted into duct 92, theremoval ofthe confining force on sail 13 allows the sail to snapo'utri'nto a position as shown in FIGURE 1 except the sail is` insideductl 9,2.' i

While I"have shown the invention in one particular embodiment, theintention is to limit the scope of the present invention only by theappended claims in which I claim:

1. In a combined moisture and air iiow responsive controldevice,

a switch mounted in a switch enclosure and having an operating leverprotruding from said enclosure, a base member attached to and extendingfrom Isaid switch enclosure, said lever extending into one end Vo'fs'aidbase member, y

a moisture responsive element mounted iisaid base member,

a iirst lever pivotally attached to said base member at said one end toengage said operating lever, means connecting said element to said basemember and said first lever whereby said switch is operated when themoisture level of air`surrounding said element is of aselectedvaluetoAchange the length of said element to av predetermined value,

a collapsible metal framework formed by a V shaped length of resilientwire,

a flexible material supported by said framework, said wire providing abias means to extend said framework and said material to provide a sail,v

second ylever `means lattached to said base member and pivotallyconnecting said framework. to be supported by said base member,

and means connecting said second lever means to said operating lever foroperating said switch upon the presence of a predetermined amountoflairiiow.'

2. In a control device,

a base,

a control elementsupport,

means connectingsaid support to said base, said vsupport being padaptedto be inserted into' a hole in an air lfiowpassageway,

a lever pivotally attached tosaid base,

switch means operable uponimovementof said .lever to a predeterminedposition, said switch means being attached to said base,

a humidity responsive element mounted on said support, Y

means connecting said elementto said lever whereby said element movessaid lever' to operate said switch means uponv the humidity of the airbeing a predetermined value,

a `support structure pivotaliy connected to saidsupport,

a thin iiexible material 4supported by said structureto form a sail,

and means `connecting said 4structure to said switch means to Voverridethe effect lof said humidity element on said switch means, saidstructure being col.

laps'ible to lay adjacent said ysupport whereby said support includingsaid humidity, element land sail are ladapted 4to be linsertedv into thehole and thenlsaid sail extends to be effective Vupon the'presence 'ofair flow to operate said switch means.

3. In an air lio'wresponsive device,

a base,v

an electrical switch device to be operated upon the presence of air flowmounted in said` base,

a collapsible structure `movably mounted, onpsaid base 'and'connected tosaid electrical switch devicesaid structure comprising a V shaped`length of wire mountedwith the free ends ofsaid wire extending outward,

and a thin -fiexible material connected to said'I Vshaped Wire forming asail to respond to iair HowtoV operate said device when said sail movesas air impinges o'n said material, said Isail Vcan becollapsed vtolreduce the size vof said sail during transportation and 'nstallatsn .byAi 11,1..1i ns Said tree endspf saidwire reggina.

ltfsfeneafted .bythe Examiner UNITED STATES PATENTS Y 1,213,642 1/17Hoeft 20o-81.9 2,031,408 2/36 Eggleston 732-336.

2,038,111 4/36 Hopkins Vet al. v73--228 BERNARD A. GILHEANY, PrimaryExaminer. ROBERT K. SCHAEFER, Examiner.

1. IN A COMBINED MOISTURE AND AIR FLOW RESPONSIVE CONTROL DEVICE, ASWITCH MOUNTED IN A SWITCH ENCLOSURE AND HAVING AN OPERATING LEVERPROTRUDING FROM SAID ENCLOSURE, A BASE MEMBER ATTACHED TO AND EXTENDINGFROM SAID SWITCH ENCLOSURE, SAID LEVER EXTENDING INTO ONE END OF SAIDBASE MEMBER, A MOISTURE RESPONSIVE ELEMENT MOUNTED IN SAID BASE MEMBER,A FIRST LEVER PIVOTALLY ATTACHED TO SAID BASE MEMBER AT SAID ONE END TOENGAGE SAID OPEATING LEVER, MEANS CONNECTING SAID ELEMENT TO SAID BASEMEMBER AND SAID FIRST LEVER WHEREBY SAID SWITCH IS OPERATED WHEN IS OF ASELECTED VALUE TO CHANGE THE LENGTH OF SAID ELEMENT TO A PREDETERMINEDVALUE, A COLLAPSIBLE METAL FRAMEWORK FORMED BY A V SHAPED LENGTH OFRESILIENT WIRE, A FLEXIBLE MATERIAL SUPPORTED BY SAID FRAMEWORK, SAIDWIRE PROVIDING A BIAS MEANS TO EXTEND SAID FRAMEWORK AND SAID MATERIALTO PROVIDE A SAIL, SECOND LEVER MEANS ATTACHED TO SAID BASE MEMBER ANDPIVOTALLY CONNECTING SAID FRAMEWORK TO BE SUPPORTED BY SAID BASE MEMBER,AND MEANS CONNECTING SAID SECOND LEVER MEANS TO SAID OPERATING LEVER FOROPERATING SAID SWITCH UPON THE PRESENCE OF A PREDETERMINED AMOUNT OF AIRFLOW.